Epiphytes are entities dwelling on the surface of other plants such as branches, tree trunks etc for space and shelter only. This is why they are also referred to as space parasites. The epiphytic roots comprise a covering of dead tissue, spongy in nature known as the velamen. With the help of this, they are able to absorb water from dew, moist atmosphere and also rain. In a few other instances, they are also referred to as “air plants” as they are not anchored to the soil.
1. The presence of epiphytic roots is the characteristic feature of_________.
(a) Cuscuta, in which haustoria is present
(b) Pinus, in which mycorrhizal association is present
(c) Orchids, in which velamen tissue is present
(d) Jussiaea, in which floating roots are present
Answer: (c)
2. Velamen is a special layer of absorptive tissue, consisting of 4 or 5 layers of long polygonal cells, which are formed by the _________.
(a) Stem
(b) Absorbing roots
(c) Hanging roots
(d) Clinging roots
Answer: (c)
3. A plant with epidermis specialised to absorb moisture from the air is______.
(a) Rhizophora
(b) Jussiaea
(c) Vanda
(d) Avicennia
Answer: (c)
4. What is the outer covering of the epiphytic root called?
(a) Velamen
(b) Rhizophore
(c) Semaphore
(d) Pneumatophore
Answer: (a)
5. A root cap is not found in the root of
(a) Stilt root of Pandanus
(b) Seminal roots
(c) Hanging prop root of Banyan
(d) Epiphytic roots
Answer: (d)
6. This is a function of velamen
(a) transpiration
(b) exchange of gases
(c) absorption of moisture from air
(d) absorption of water from soil
Answer: (c)
7. Epiphyllous roots in Begonia and Bryophyllum are
(a) Modified leaves
(b) Green roots
(c) Roots arising from leaves
(d) Roots bearing stem
Answer: (c)
8. Aerial absorptive roots occur in
(a) Mesophytes
(b) Epiphytes
(c) Xerophytes
(d) Hydrophytes
Answer: (b)
9. This root modification does not store food
(a) Napiform
(b) Tuberous
(c) Stilt
(d) Conical
Answer: (c)
10. Identify the correct statement
(a) Velamen roots attach to the soil
(b) In Cuscuta, velamen roots are present
(c) Velamen roots are tap roots
(d) Velamen roots are living
Answer: (d)
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